The maintenance of railroad track ballast is an ongoing and important element of railroad transportation safety. The ballast material associated with railroad track lines, typically crushed rock or gravel, helps to provide horizontal and vertical support to the railroad line and also provides a drainage mechanism to help remove damaging moisture away from the railroad track and ties. Periodically, the ballast along a length of track, or in single spot locations, may become fouled with dirt, oil, debris, or other matter that can reduce the draining properties or supporting ability of the ballast. Therefore, railroad operators must periodically replace or recondition this fouled ballast in order to maintain the integrity and safety of the railroad line. The repair of rail line ballast is not easily accomplished with traditional earth-moving equipment. The rail and tie configuration of railroad lines requires the use of specialized equipment if the rail and tie assembly is to remain in place during reconditioning. Because of the time and cost involved in removing and constructing railroad lines, it is highly desirable to leave the rail line in place during reconditioning and to minimize or eliminate the time when the line is unavailable for rail traffic.
Currently in the marketplace, there are a variety of machines and techniques for removing railroad track ballast. For example, one approach is to remove a short section of track ballast and insert a plow or sled towed by a specially equipped railcar to push or force the ballast to the outside edges of the track. A second example of a ballast removing device is a “chainsaw” type mechanism where a long blade supports a rotating chain or belt that can be manipulated to “cut” ballast out from underneath the rails and ties of an existing track. Representative prior art maintenance and removal systems for railroad ballast include U.S. Pat. Nos. 3,967,396, 4,119,154, 4,858,344, and 6,862,822, each of which is herein incorporated by reference.
Generally, the plow or sled approach for removing ballast is limited to situations where a long stretch of track is to be reconditioned due to the fact that the effort required to initially place the plow under the rail line is not typically justifiable for short segments of track. While the chain equipped ballast cutter may be more suitable for short distance ballast removal it can be subject to chain or belt breakage requiring maintenance to replace or repair of the cutting assembly. Thus, neither of these existing technologies satisfies the need for a ballast removing apparatus capable of being reliably and cost effectively used for both short and long distance ballast removal.
In certain track layout configurations it is also inconvenient to use either the ballast plow or a large chain driven cutting apparatus. For example, in areas such as rail yards, sidings, and other locations where multiple lines run in parallel to each other in close proximity it can be difficult to maneuver a large cutting machine into position between the rail lines or there may be inadequate space on either side of the railroad line to deposit the fouled ballast as it is removed from underneath the rails.
Therefore, an unsolved need exists for further improvement to existing railroad ballast removing systems. The system should be able to quickly and effectively remove ballast from underneath existing rail lines and to provide an easily maneuverable cutting or cutting apparatus that is capable of operating in restricted areas. Additionally, the system should be configured such that the risk of breakage is minimized and such that it is easily maintained or serviced when necessary. By eliminating the use of a belt or chain assembly maintenance time and cost can be reduced, further reducing costs associated with rail line maintenance and reconditioning.